Transfer set incorporating colour reaction sheets

ABSTRACT

ACCORDING TO THE INVENTION A TOP SHEET AND AT LEAST ONE COPY SHEET OF A SET OF PRINTED FORMS, OR OTHER TRANSFER SET, OF COLOUR REACTION PAPER ARE INTEGRALLY JOINED ACROSS A FOLD LINE. THE COLOUR RECEIVING LAYER ON THE TOP SURFACE OF THE COPY SHEET IS ALSO APPLIED IN A SINGLE OPERATION, BEFORE THE FOLDING, THE LOWER SURFACE OF THE TOP SHEET. OVER THE RECEIVING LAYER ON THE LOWER SURFACE OF THE TOP SHEET THERE IS SUBSEQUENTLY APPLIED A LAYER OF A NEUTRALISING AGENT AND OVER THE NEUTRALISING AGENT LAYER, AT THOSE PARTS OF THE TOP SHEET WHICH ARE INTENDED FOR TRANSMITTING THE TYPED MESSAGE, A PRINTED COLOUR FORMING LAYER.

E. KUNKEL Aug. 8, 1972 TRANSFER SET INCORPORATING COLOUR REACTION SHEETS Filed July 2'3, 1970 FIG! II I III/I 1 I Ila/1111111 llllllllllllllllllllll FIG.3

I l 1 I I 11111111111111!!!11111111111111]!!!lIII lLLll Ill]!!! United States Patent Int. 01. B41m 5'/22 US. Cl. 117-36.} 18 Claims ABSTRACT OF THE DISCLOSURE According to the invention a top sheet and at least one copy sheet of a set of printed forms, or other transfer set, of colour reaction paper are integrally joined across a fold line. The colour receiving layer on the top surface of the copy sheet is also applied in a single operation, before the folding, to the lower surface of the top sheet. Over the receiving layer on the lower surface of the top sheet there is subsequently applied a layer of a neutralising agent and, over the neutralising agent layer, at those parts of the top sheet which are intended for transmitting the typed message, a printed colour forming layer.

The invention relates to a transfer set incorporating colour reaction sheets, the set consisting of a top sheet and at least one copy sheet, the under surface of the top sheet being coated, over at least a part of its area, with a colour forming layer, and the upper surface of each copy sheet being coated with a colour receiver.

A set of the kind described above usually consists of three different kinds of sheets: a top sheet, one or more intermediate sheets and a bottom sheet. The under surfaces of the top and intermediate sheets are coated with a colour forming layer, whereas the upper surfaces of the intermediate and bottom sheets are coated with a colour receiving layer consisting essentially of a clay, or an acid treated clay which has adsorbent properties. The upper surface of the top sheet and the'under surface of the bottom sheet are uncoated, although the upper surface of at least the top sheet may carry a printed message when the tarnsfer set is a set of printed forms. The colour forming layers on the under surfaces of the top and intermediate sheets consist, in the known way, of a solution of colour forming substances contained in microcapsules, which are applied in the form of a dispersion, or alternatively th solution of colour forming substances can be contained in an emulsion or in a spongy layer of a synthetic plastic material, or in a layer of a meltable binder. The colour receiving layers on the upper surfaces of the intermediate and bottom sheets consist of pigment-forming materials which react with the colour forming layer, the nature of the reaction'depending on the particular substances used. These reactions are known and are not a part of the present invention.

In the manufacture of transfer sets it is known to arrange that only certain parts of the message typed into the upper surface of the top sheet come through, that is to say only certain parts of the typed message appear on the individual copy sheets. In the case of the customary transfer sets, which have carbon layers, or which contain carbon intermediate sheets, there is used for this purpose a process known as carbonising printing. In this known process carbon layers are applied to selected areas on the under surface of the sheet.

Difficulties are enconutered in attempting to apply this carbonising printing process to colour reaction papers. Nevertheless a method is known, which has been called the hot-spot-printing process, forapplying a colour forming layer to selected areas of the under surface of a sheet.

However a special requirement which often occurs in the utilisation of sets of printed forms is that the top sheet must remain firmly attached to at least one copy sheet. This requirement occurs for example in the case of shippers forms and in the case of the transfer forms used in banking operations. Attaching the several sheets together by means'of adhesives or by stapling is unsatisfactory, in particular because they can too easily become detached. For this reason it has not hitherto been practicable to manufacture transfer sets of this type, using colour reaction papers, that is to say papers which are coated on alternative surfaces with colour forming layers and colour receiving layers.

The object of the present invention is to provide transfer sets capable of satisfying the special requirement mentioned above, using colour reaction sheets for the sake of their special advantages.

In accordance with the invention, a transfer set of colour reaction sheets comprises a single sheet folded to form a top sheet and at least one copy sheet, the surface of the single sheet which forms the lower surface of the top sheet and the upper surface of the copy sheet being coated with an integral colour receiving layer, which, on the lower surface of the top sheet, is covered with a layer of a neutralising agent for preventing the colour reaction, those parts of the top sheet which are intended for transmitting the typed message being provided with a printed colour forming layer superposed over the neutralising layer.

When the single sheet is folded to form at least two copy sheets, both surfaces of the single sheet are coated with colour receiving layers and the lower surface of the or each intermediate copy sheet is provided with a layer of a neutralising agent partly overprinted with a colour forming layer.

The transfer set may be manufactured as follows. To one surface of a single sheet of paper or foil there is first of all applied, by a suitable machine, a coating of material to form a colour receiving layer, as mentioned at the beginning for the copy sheet. In the next operation the under surface of the part of the single sheet which will become, after folding, the top sheet is coated with a neutralising agent layer, which is superposed over the existing colour receiving layer. When this has been done the neutralising areas can no longer act as colour receiving areas when they come into contact with a colour forming layer, because in these areas the colour receiving layer has been covered over and neutralised by the superposed neutralising layer. In a further operation a special colour forming layer is applied to parts of the neutralising agent layer by the hot-spot printing process. The ribbon which has been treated in this way is then folded so that the coated surfaces come together. The folding can produce one or more creases, depending on how many copy sheets are required. For example if only one copy sheet is required the original sheet is folded along its middle, giving a top sheet and a copy sheet which are firmly attached together. Consequently when typing is applied to the top sheet at the locations where the colour forming layer has been applied on the under surface of the top sheet, this layer reacts with the colour receiving layer on the upper surface of the copy sheet, giving a visible message on the copy sheet. A visible message on the copy sheet can be produced only under those areas of the top sheet where the colour forming layer has been applied to its under surface. The neutralising layer constitutes a reliable barrier layer separating the superposed colour former layer from the subjacent colour receiver layer.

In the case of a transfer set which has to contain several copy sheets, intermediate sheets can be provided either by inserting extra sheets, or by the multiple folding method mentioned above.

In the process of manufacture it has been found advisable to ensure that no part of an overprinted colour forming layer extends to any edge of the neutralising agent layer over which it is printed. Preferably, the neutralising agent layer occupies an area between 1 and 2 mm. wider and longer than the superposed colour forming layer, which consists of a special mixture of materials. It has also been found advisable to tint the neutralising agent slightly, by adding a dye, so as to make it easier for the printer to control his operations.

The neutralising agent mentioned above is a liquid and is applied by a method similar to that used for the so called Flexodruck colours. The neutralising substance contains a film former dissolved in an organic solvent. The film former can be a resin, preferably a non-saponifiable resin, such as a ketone resin. Alternatively however if desired the film former can consist of an easily soluble synthetic resin, for example polyvinylpyrrolidone, but this synthetic resin must also be non-saponifiable. If desired there can be used as binders or film formers mixtures of non-saponifiable resins with non-saponifiable synthetic substances, provided that the substances used are easily soluble in low boiling organic solvents and are compatible with each other.

As solvents for the neutralising agent there'can be used a non-saponifiable alcohol, preferably ethyl alcohol, but alternatively if desired isopropyl alcohol, or mixtures of these two can be used. The solvent should have a low boiling point to ensure that the printed layer dries quickly.

The neutralising agent may contain, in addition to the film former and the solvent, five to twenty percent of a hygrophilic plasticiser, for example polyethylene glycol. The active neutralising agent may be a base, for example an amine, preferably triethanolamine. However other basic substances can be used, provided that they are easily soluble in organic solvents, and provided that they are compatible with the particular film former.

To facilitate the printers task there may be added to the neutralising agent a pigment in the form of a highly dispersed silicic acid product which provides a very large surface area, for example Aerosil. we

A neutralising :agent of this kind covers the colour receiver layer sufliciently when applied in a thickness corresponding to 3 to 7 g./m. preferably 4 to 5 g./m. Over the neutralised surface a colour forming layer can be printed by the hot-spot printing method.

Some examples of transfer sets in accordance with the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a cross section representing diagrammatically the principle of a transfer set according to the invention;

FIG. 2 is a perspective view showing a single-piece folded set; and

FIG. 3 is a cross section through a further example of a set according to the invention.

In the example shown in FIG. 1 a top sheet 1 is coated on its lower surface with a colour receiving layer 2, and over that a neutralising layer 3, and finally a colour forming layer 4. The upper surface of the copy sheet is coated with a colour receiving layer. The two sheets will in fact be connected across a fold line as shown in FIG. 2.

The example shown in FIG. 2 is a single-piece set which has been folded along a line to form a top sheetand a copy sheet. The coatings are as described for FIG. 1.

Finally, representing a further development of'the invention, (FIG. 3 shows a single-piece set which has been folded along two lines to form a top sheet and two copy sheets. If desired further copy sheets can be added underneath.

there will now follow three For further clarification recipes, one for each of the three layer substances:

1 COLOUR RECEIVING LAYER 2 The main characteristic of this layer is a clay which has been treated with mineral acids. This substance acts as a pigment-forming "ingredient, which reacts with the spirodinaphthopyranes which are used as the colour formers,'the product of the reaction being coloured salts.

The colour receiving layer can have the following composition (parts, by weight).

Clay treated with inorganic acids 85.2 Methyl cellulose 1.2 Polyvinyl alcohol 4.8 A dispersion of polyvinyl acetate 6.1

Alternatively, instead of methyl cellulose-and-polyvinyl alcohol, other substances can be used as the binder, for example the known. water soluble binders such as starch, starch ether or carboxymethyl cellulose or the like. Furthermoreit is not. absolutely necessary to use a dispersion of polyvinyl acetate, instead of this there can for example be used a dispersionof acrylic acid ester or dispersions of mixed polymers. However the binder must be compatible with the acid treated clay.

If desired there can be added to the above mixture up to 3% of acids in solid form, for example amidosulphonic acid, oxalic acid, maleic acid, sulphosalicicacid or the like. The whole is mixed and ground and applied to the sheet of paper or foil using the coating devices customary in. the paper industry. a

(2) NEUTRALISING LAYER 3 For neutralising the colour receiving layer mentioned in section 1 above it is necessary to use a basic substance which neutralises the acidity of the acid treated mineral clay, so as to prevent the spirodinaphthopyrane from reacting with the colour receiver layer, forming salts.

Substances which react as bases and which have proved in practice to be suitable as neutralisers are the aliphatic and aromatic amines, particularly amines derived from the fatty acids. 1

I A neutralising mixture particularly suitable for application by the Flexodruck method, and which contains basic substances, has the. following composition (parts by weight): u

Polyvinylpyrrolidone 8.5 Spirits p v 18.0 Polyethylene glycol 1.7 Triethanolamine 1.0 Highly dispersed silicic acid 0.8

The mixture is a liquid, with a viscosity of approximately 240 cp., although the viscosity can if desired be higher or lower.

. To make the printedarea more easily recognisable the neutralising substance can if desired be slightly .tinted using a spirits soluble dye. I

3 COLOUR FORMING LAYER 4' (Special coating substance containing a colour former) 1 This substance has the following composition (parts by weight): 1 1

Montan wax I I V I 63 Chlorinated paraflin containing 40 to 42% chlorine V v 33 upper surface of the copy sheet, said colour receiving layer consisting of clay treated with mineral acid and reactive with spiro-dinaphthopyrane to form a coloured salt and a 'binder, a neutralizing layer for preevnting colour reaction extending upon said lower surface over a portion of said colour receiving layer and comprising a substance belonging to the group consisting of aliphatic and aromatic amines, and a colour forming layer extending upon said lower surface over a portion of said neutralising layer and comprising montan wax, chlorinated parafiin containing 40 to 42% chlorine and a spirodinaphthopyrane.

2. A transfer set according to claim 1, in which said neutralising agent contains a film former dissolved in an organic solvent, a hygrophilic plasticiser, and a neutralising active substance.

3. A transfer set according to claim 2, in which said neutralising agent also contains a highly dispersed silicic acid product and a dye.

4. A transfer set according to claim 2, in which said film former is a non-saponifiable resin.

5. A transfer set according to claim 4, in which said film former is a ketone resin.

6. A transfer set according to claim 2, in which said film former is an easily soluble non-saponifiable synthetic substance.

7. A transfer set according to claim 6, in which said film former is polyvinylpyrrolidone.

8. A transfer set according to claim 2, in which said film former is a mixture of a non-saponifiable resin with a non-saponifiable synthetic substance, the mixture being easily soluble in a low boiling organic solvent.

9. A transfer set according to claim 2, in which said solvent consists of a non-saponifiable low boiling alcohol.

10. A transfer set according to claim 9, in which said non-saponifiable alcohol is ethyl alcohol or isopropyl alcohol or mixtures of the two.

11. A transfer set according to claim 2, in which said neutralising agent contains, in addition to said solvent and said film former, between 5 and 20% of a hygrophilic plasticiser.

12. A transfer set according to claim 11, in which said plasticiser is a polyethylene glycol.

13. A transfer set according to claim 2, in which said neutralising agent contains, as the neutralising active substance, a basic substance which is easily soluble in organic solvents and is compatible with the film former.

14. A transfer set according to claim 13, in which said neutralising active substance is a liquid amine.

15. A transfer set according to claim 14, in which said liquid amine is triethanolamine.

16. A transfer set according to claim 3, in which said silicic acid product is a pigment which has a large surface area.

17. A transfer set according to claim 2, in which said neutralising agent layer has a density of between 3 and 7 g./m.

18. A transfer set according to claim 17, in which said density is between 4 and 5 g./m.'

References Cited UNITED STATES PATENTS 2,293,060 12/ 1966 Harbort 117-362 3,539,375 11/1970 Baum 11736.2 3,364,052 1/ 1968 Martino 117--3 6.2 2,074,97 1 3/ 1937 Peltom 117-3 6.4 2,327,215 8/ 1943 Potter 11736.4 2,606,775 8/ 1952 Newman 1l736.4

MURRAY KATZ, Primary Examiner US. Cl. X.R. 

